Midea V8 VRF Series Service Manual page 58

V8 VRF Indoor Units
Note:
1. The plug attached to the WATER port of the main control board corresponds to the following two cases:
a. The factory default of IDUs without a water level switch uses a short-circuit plug to seal the WATER port.
b. IDUs with a water level switch use a water level switch plug to seal the WATER port.
2. Use a multimeter to measure the resistance between the pins corresponding to the two wires of the water
level switch plug. 1) After the floater of the water level switch is moved upwards to the highest position, the
water level switch is in a short-circuited state, and the resistance value is infinite. 2) After the floater of the
water level switch is moved downwards to the lowest position, the water level switch is closed, and the
resistance value is less than 0.25 Ω. If the detected resistance value does not meet the above values, the
water level switch is damaged.
3. Possible causes and solutions for the situation where the pump outlet does not discharge water or the
discharge flow is very small: 1) The water pump plug to the PUMP port in the IDU main control board is
loose. Reconnect it firmly. 2) The drain pump suction impeller is clogged. Remove the debris causing the
clog to make the pump continue running. 3) If the error cannot be cleared after implementing solutions for
causes 1) and 2), the drain pump body is damaged. Replace the drain pump.
4. Possible causes and solutions for abnormal drainage due to non-standard installation: 1) If the drain pipe
is blocked, remove the debris and clean the drainage pan and the drain pipe of the IDU. 2) If the drain pipe is
improperly installed, which causes the condensate water to flow backward, tilt the IDU to the drainage side
by a certain gradient (inclination ≥ 1%). The centralized drain pipe must be lower than the drainage outlet of
the unit. Air outlets must be placed at the highest horizontal pipeline (see Installation and Operation Manual
of IDUs). 3) If the lift of the drain pipe exceeds the allowable value, reduce the vertical height of the drain
pipe or replace the drain pump with the one which has a higher lift.
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